Techniques of detecting the position or the like of an object touching or in proximity to a surface of a display have been heretofore known. Among them, as a typical and widespread technique, a display including a touch panel is cited.
There are various types of touch panels, but as a commonly used type, a touch panel of a type detecting capacitance is cited. When a finger touches the touch panel, the touch panel captures a change in a surface electric charge of the panel to detect the position or the like of an object. Therefore, when such a touch panel is used, users are allowed to intuitively operate the touch panel.
Moreover, the applicant of the invention has proposed displays having a display function of displaying an image and an image pickup function (a detection function) of picking up an image of an object (detecting an object) in Patent Document 1 and Patent Document 2.    [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2004-127272    [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2006-276223